Tuesday, July 4, 2017

Cool science in June!

The humidity is high, fireworks are lighting up the sky, and the wonderful smells of charcoal and burgers fill the air. It's summer! But more importantly, it's time for a short review of some interesting science published in June. We'll start with tomatoes, because who doesn't love a burger with a slice of tomato?

Farmers and agriculturalists often select desired variants of a crop or other plant species they want to breed and further develop. Bigger tomatoes, new varieties of grapes for wine, drought-resistant wheat and barley, more potent strains of marijuana... there are hundreds of versions of many different plants. Gregor Mendel, the father of genetics, cultivated a handful of select traits in the pea plant (height, pea shape, and pea color to name a few) so that he could study the laws of inheritance.

When two desired versions of the same plant are combined together, say a drought-resistance variety of corn and a variety that grows bigger ears, the two can be bred together to get a super-variety: corn that yields larger ears AND is drought-resistant. But sometimes that combination of two desired traits develops nothing of value.

Such is the case with a few varieties of the tomato plant and researchers from around the world used CRISPR to study the molecular mechanisms that contributed to those undesirable outcomes. The authors were able to engineer a work-around to allow the new hybrid tomato plant to successfully grow and produce a higher yield of tomatoes compared with the two individual strains. This is an exciting use of CRISPR technology in food science and may better help us create crops that will still grow as our climate changes or allow these crops to resist insects and other pests. All of this is very important for our survival as a species.

But back in medicine, the controversies of CRISPR continue to develop. There was a brief article in Nature that presents evidence that CRISPR can cause off-target mutations in the genomes of mammalian cells. This is a really big deal, considering any therapy or gene-editing option using CRISPR will need to be 100% efficient in order to prevent mutations that could lead to diseases like cancer. This is one of the first papers specifically studying the off-target effects of the CRISPR gene-editing system. However, the results here need to be taken with a grain of salt as the authors only submitted their work on a small number of animals and they lacked a few important controls to fully support their conclusions.

Dr. George Church's research group uploaded a response to this article, pointing out the article's flaws, on the bioRxiv.org website. But this article also needs to be taken with a grain of salt, as the bioRxiv is a pre-peer review publication website. This means this manuscript has not been peer-reviewed nor is it published yet in a peer-review journal. So at best, Church's response can be called an opinion piece until it's formally published refuting the first article. (If you are interested in how the bioRxiv fits into the peer review process, please check out my blog post over at the Cosmic Roots website).

I'll comment that discourse like this is really great for the scientific field and hopefully spurs more interest in reproducing each lab's results. Researchers challenging another's work in a respectful way will help the technology advance. But until then we must all approach this with a healthy skepticism.

Okay, onto bacteria!

The human microbiome is an exploding topic in research these days.  Our gut bacteria can influence how we respond to the drugs that we take and our susceptibility to disease due to our diet. Additionally, bacteria on our skin can also influence our response to drugs and research is underway examining how that relationship impacts our everyday health. A new study studied the impact of the bacteria E. Coli on the lifespan of the worm, C. elegans, which eats E. coli as food.Mutations in different strains of E. Coli increased the lifespan of the worms that ate the mutants. Evidence is presented that a secreted metabolite made within the mutant bacteria, colanic acid, increases mitochondrial function in the worm to promote their longevity. That's pretty amazing and offers a very intriguing hypothesis that healthy bacteria in our gut could be providing us with anti-aging metabolites.

A few other nuggets of interest:

-Scientists have extended the ability to transmit and identify entangled particles at a range of 1200 kilometers using satellite transmission: per their report, this could be the beginnings of a new communication network.

-On a similar note, researchers have published on a new method to conduct wireless power transfer. I won't even attempt to explain the math or the technical garble in this paper, but the results here are a new avenue to remotely power objects across potentially large distances. Really cool!

-Scientists have published the structure of the cytomegalovirus virus (CMV). This virus is quite common in humans and can impact our immune response as we age, not to mention the virus is responsible for a host of other conditions. The virus is also related in shape to the herpes viral family and may offer new insight in combating herpes.

-We are a few steps closer to exoskeletons that could assist humans with work or help those with disabilities regain mobility. This new model helped humans with walking and running and load-bearing tasks!

And last of all, a new report assessing the potential global impact of climate change on a county-to-county level in the United States. It's a very necessary first step in combating the pseudoscience and false beliefs about the impact of our warming world and it does a fair job at applying economic forecasting to project county GDP and mortality rates by the end of the century. The model accounts for changes in county GDP for each 1 degree rise in mean global surface temperature, and no surprise that the southeastern portion of the United States would take the brunt of the impact.

That's partially due to the susceptibility of the south and east coast to damage from major storms, rising ocean levels, and decreases in crop yields during long periods drought and heat. However, the model also tries to adjust for local temperature changes, social unrest, and other demographic factors that can influence response to climate change. The model doesn't account for how migration and new technologies may impact the U.S., nor does it take into account major international changes that could also influence county-level differences in the long-term. However, the authors are developing future models that incorporate those important factors. Either way, it's not good news if you live in the south, east, or the Midwest!

That's it for now, have a great Fourth of July!